Objective To establish a finite element model of the T2-L5 thoracolumbar spine and verify its validity,to provide numerical model support for exploring the dynamic response characteristics and injury mechanism under spinal impact loads.Methods A three-dimensional(3D)finite element model of the T2-L5 thoracolumbar spine was established based on CT scanning data.The load-rotation angle curve of the T12-L1 segment under different moments(flexion,extension,rotation,and lateral bending conditions)was calculated and compared with the data reported in the literature.Free-fall loads at different heights were applied to the finite element models of the T2-6,T7-11,and T12-L5 spine.The peak axial force and bending moment were obtained by finite element simulation analysis and compared with data reported in the literature.Results The maximum rotation angle of the T12-L1 finite element model was-2.24°-1.55° under moments in different directions,which was in good agreement with the literature data.The peak axial force of T2-6,T7-11,and T12-L5 spine finite element models subjected to different free-fall loads was 1.7-5.3 kN,1.3-5.5 kN,and 1.3-7.5 kN respectively,which were within the error range reported in the literature.Stress nephograms of the spine and intervertebral discs showed that the vertebral body was first stressed from the outer edge.The intervertebral disc was subjected to the main load by the nucleus pulposus,consistent with the actual spinal injury mechanism.Conclusions The T2-L5 spine model established in this study can correctly simulate the biomechanical behavioral characteristics of the spine under different working conditions,and the analysis results are effective.

In June 2022, a carbon monoxide poisoning accident with hidden source occurred in a bonded gold/silver wire manufacturing enterprise in Guangzhou, causing 10 people to be poisoned, of which 1 was caused by carbon monoxide poisoning and 9 by carbon monoxide contact reaction. The symptoms were dizziness, fatigue and vomiting. After 5 to 7 h, the saturation of carboxyhemoglobin in finger pulse was 4% to 10%, and the saturation of carboxyhemoglobin in blood gas biochemical analysis was 1.9% to 5.8%. The concentration of carbon monoxide detected in the carbon borne purification plant of the enterprise was 34.46-37.26 mg/m 3. It was judged that the accident was carbon monoxide poisoning caused by carbon monoxide gas being transported to the work post along the gas transmission pipeline due to abnormal operation of the carbon borne purification plant. By investigating the source and cause of poison, this paper provides a warning for the similar process to prevent similar events, and provides a new idea for the identification of chemical poisoning risk. At the same time, it is warned that similar enterprises should fully consider the risk of poisoning under specific circumstances, strengthen equipment maintenance and repair, and prevent the occurrence of similar incidents.

In June 2022, a carbon monoxide poisoning accident with hidden source occurred in a bonded gold/silver wire manufacturing enterprise in Guangzhou, causing 10 people to be poisoned, of which 1 was caused by carbon monoxide poisoning and 9 by carbon monoxide contact reaction. The symptoms were dizziness, fatigue and vomiting. After 5 to 7 h, the saturation of carboxyhemoglobin in finger pulse was 4% to 10%, and the saturation of carboxyhemoglobin in blood gas biochemical analysis was 1.9% to 5.8%. The concentration of carbon monoxide detected in the carbon borne purification plant of the enterprise was 34.46-37.26 mg/m 3. It was judged that the accident was carbon monoxide poisoning caused by carbon monoxide gas being transported to the work post along the gas transmission pipeline due to abnormal operation of the carbon borne purification plant. By investigating the source and cause of poison, this paper provides a warning for the similar process to prevent similar events, and provides a new idea for the identification of chemical poisoning risk. At the same time, it is warned that similar enterprises should fully consider the risk of poisoning under specific circumstances, strengthen equipment maintenance and repair, and prevent the occurrence of similar incidents.

Objective:To discuss the effect of low-dose ionizing radiation on the health of radiation workers, and provide a basis for occupational health risk assessment of radiation workers.Methods:In January 2020, 3165 radiation workers who performed radiation occupational health examinations in Guangzhou Prevention and Treatment Hospital for Occupational Disease from January 2017 to December 2019 were selected as the research objects, and compared and analyzed the health status of radiation workers with different examination types (pre-job, in-job and off-job) , types of work, gender, and length of service.Results:The off-job occupational radiological health examination was rare at 2.3% (74/3165) . The abnormal detection rate of chest radiographs, renal function, thyroid function, and blood routine of the radiation workers in-job group was higher than that of the pre-job group ( P<0.05) . No statistical difference was found in the abnormal detection rate of the examination items during the in-job group and the off-job group ( P>0.05) . The blood routine abnormality detection rate of medical application group and industrial application group were higher than those of nuclear fuel group ( P<0.05) . The abnormal detection rate of blood pressure and renal function of male radiation workers was higher than that of females, while the abnormal detection rate of blood routine of females was higher than that of males ( P<0.05) . The abnormal detection rate of electrocardiogram, chest radiograph, blood pressure, renal function, thyroid function, and blood routine of radiation workers increased with increasing working age ( P<0.05) . Conclusion:Occupational health status of radiation workers is not optimistic. Radiation occupational health monitoring should be strengthened, special attention should be paid to off-job radiation occupational health examination, focusing on the sensitive indicators of sensitive personnel, improving radiation protection conditions, and effectively protecting the occupational health of radiation workers.

Objective:To discuss the effect of low-dose ionizing radiation on the health of radiation workers, and provide a basis for occupational health risk assessment of radiation workers.Methods:In January 2020, 3165 radiation workers who performed radiation occupational health examinations in Guangzhou Prevention and Treatment Hospital for Occupational Disease from January 2017 to December 2019 were selected as the research objects, and compared and analyzed the health status of radiation workers with different examination types (pre-job, in-job and off-job) , types of work, gender, and length of service.Results:The off-job occupational radiological health examination was rare at 2.3% (74/3165) . The abnormal detection rate of chest radiographs, renal function, thyroid function, and blood routine of the radiation workers in-job group was higher than that of the pre-job group ( P<0.05) . No statistical difference was found in the abnormal detection rate of the examination items during the in-job group and the off-job group ( P>0.05) . The blood routine abnormality detection rate of medical application group and industrial application group were higher than those of nuclear fuel group ( P<0.05) . The abnormal detection rate of blood pressure and renal function of male radiation workers was higher than that of females, while the abnormal detection rate of blood routine of females was higher than that of males ( P<0.05) . The abnormal detection rate of electrocardiogram, chest radiograph, blood pressure, renal function, thyroid function, and blood routine of radiation workers increased with increasing working age ( P<0.05) . Conclusion:Occupational health status of radiation workers is not optimistic. Radiation occupational health monitoring should be strengthened, special attention should be paid to off-job radiation occupational health examination, focusing on the sensitive indicators of sensitive personnel, improving radiation protection conditions, and effectively protecting the occupational health of radiation workers.

Objective To prepare a wound dressing using nitrocellulose as a membrane and optimize its formulation. Methods Partial analysis was performed on commercial available products. The wound dressings were prepared by using nitrocellulose as a film-forming material, benzyl alcohol as a bacteriostatic agent, castor oil as a plasticizer, isopropyl palmitate as a skin emollient, camphor as a fragrance, and isopropyl alcohol, ethyl acetate and butyl acetate as volatile solvent. The tensile strength, breakpoint elongation percentage, breathability and waterproof performance were tested and evaluated. Results The film-forming performance of the prepared liquid wound dressing was good. The final use amount of nitrocellulose was determined to be 6%. The use amount of plasticizer castor oil was determined to be 4%. Conclusion The prepared liquid wound dressing has good film-forming property, good mechanical property, good waterproof and certain breathability.

Objective: To explore the impact of welding operations on the health status of workers with low working age, and provide a basis for occupational health risk assessment for workers of low working age. Methods: Used the method of cluster sampling to randomly selected workers from an automobile manufacturing plant in Guangzhou as research subjects: 982 workers with welding posts of 1 year ≤working age ≤5 years were welding groups, 707 workers with simple exposure noise of 1 year ≤working age ≤5 years were assembly groups, and 717 workers in pre-job medical examinations were pre-job groups from June 2017 to September 2018. Then conducted occupational health checks on all subjects, investigated and detected the occupational hazards in welding posts and assembly posts. Results: There was no statistical difference between the noise over-standard rate of welding posts' (59.3%, 16/27) and the assembly posts' (47.4%, 9/19) (P>0.05) . The over-standard rate of welding fume, manganese and its inorganic compounds in welding posts was 11.11% (3/27) . The results of occupational health examination showed that the detection rate of disease or abnormal of the welding group was 78.4% (770/982) higher than 70.2% (496/707) in the assembly group and 53.0% (380/717) in the pre-job group (the value of 2 were 14.92 and 122.37, respectively, P<0.05) . The rate of hearing loss of the assembly group and the welding group were 14.7% (104/707) and 19.3% (190/982) , respectively, which was higher than that of the pre-job group (10.5%, 75/717) , and the hearing loss rate gradually increased with the increase of working age (the value of linear-by-linear association were 12.04 and 44.67, respectively, P<0.01) . Compared with the hearing loss rate of each working age of the assembly group, the hearing loss rate of each working age of the welding group was higher, and when the working age was 3 years, the risk of hearing loss in the welding group was 2.70 times that of the assembly group (P<0.01) . The rate of pulmonary dysfunction in the welding group was 19.2% (189/982) higher than that in the pre-job group (12.6%, 90/717) , and it increased with the increase of working age (the value of linear-by-linear association was 15.97, P<0.01) . Conclusion Welding work seriously damages the health of workers with low working age, increases the hearing loss of workers and the occurrence of pulmonary dysfunction; manganese and its compounds increases noise-induced damage to the hearing system.

Objective: To observe the effects of axial vascular network flap of scalp or anterolateral thigh perforator flap with fascia lata on repairing defects after radical resection of scalp carcinoma in patients. Methods: From February 2006 to December 2015, twenty-one patients with scalp carcinoma were admitted to our hospital, and the carcinoma invaded external lamina or full-thickness of skull and dura mater. After perfect preoperative examination, carcinoma and scalp tissue in 3 to 5 cm from the edge of carcinoma, external lamina or full-thickness of skull and invaded dura mater were resected and sentinel lymph nodes around carcinoma were cleaned in 3 to 4 days after admission. The postoperative defects with size reached from 11 cm×8 cm to 22 cm×18 cm. The flap transplantation was performed at the same time when quick frozen pathological examination results of resected scalp carcinoma margin tissue, skull, dura mater margin and basal tissue, and sentinel lymph nodes showed completely negative. Defects in 3 elderly patients were repaired by single or multiple axial scalp vascular network flaps, with the resected flaps size ranged from 12 cm×7 cm to 19 cm×14 cm. Defects in the other 18 patients were repaired by anterolateral thigh perforator flaps with fascia lata, with the resected flaps size ranged from 13 cm×10 cm to 23 cm×19 cm and the resected fascia lata size ranged from 8 cm×7 cm to 10 cm×10 cm. The head donor site of flap was repaired by medium thickness skin of head and back; the thigh donor site of flap was repaired by medium thickness skin of thigh on the same side. All patients gave up postoperative radiotherapy, chemotherapy, and other follow-up treatments. Results: After operation, the flap and skin in all patients survived completely, with no vascular crisis or other condition. During the follow-up for 6 months to 9 years, all patients showed good appearance except for baldness in operation area of head, with no obvious malformation in head donor site of flap and skin, no swollen external hernia in the brain tissue, and no local recurrence or distant metastasis of carcinoma. The appearance of thigh donor site of flap and skin was good, with normal muscle strength and movement of lower limbs. Conclusions Patients with scalp carcinoma were performed with radical resection of carcinoma, and axial vascular network flap of scalp or anterolateral thigh perforator flap with fascia lata were applied to repair the postoperative defects, with good appearance of head operation area and no local recurrence or distant metastasis of carcinoma.

Objective To retrospectively analyze echocardiography findings and left hearst function in patients with patent ductus arteriosus (PDA) after transcatheter closure. Methods 28 patients admitted between January 2012 and December 2012 in our hospital for PDA transcatheter closure were included. Assessment of cardiac structure, hemodynamics and cardiac function parameters during preoperation and in postoperation 3 days, 1 month and 6 months were studied. Results Statistical significant difference was found at 3 days, 1 month and 6 months postoperation when compared with pre-operation in terms of left atrial diameter, left ventricular end-diastolic diameter, left ventricular end systolic diameter and other doppler measurements ( all P < 0. 05 ) . Six-minute walk test ( 6MWT) tolerance improved when compared to preoperation level (P < 0. 05). Better improvement in LVEF and LVES was observed in patients age ≤14 years old when compared to patients > 14 years old after operation ( P < 0. 05 ) . Conclusions Transcatheter closure of PDA can improve cardiac function and correct early hemodynamic abnormalities patients in younger age group show more benefit from the procedure.

OBJECTIVETo assess the association of a disintegrin and metallo-proteinase with thrombospondin type 1 motifs (ADAMTS-1) gene polymorphism and ischemic stroke caused by large artery atherosclerosis (LAA).

METHODSIn total 767 patients and 506 controls were recruited. Single nucleotide polymorphisms (SNPs) rs416905 (T/C) and rs402007 (G/C) of the ADAMTS-1 gene were genotyped by polymerase chain reaction and DNA sequencing.

RESULTSFrequencies of the rs402007 GC+CC genotype and the C allele were significantly different between the two groups (68.84% vs. 60.67%, χ2=9.012, P=0.003, OR=1.432; 45.24% vs. 38.54%, χ2=11.208, P=0.001, OR=1.318). Binary logistic regression has confirmed that the above difference was significant (P=0.001, OR=1.521, 95%CI: 1.183-1.955). The frequencies of TC+CC and GC+CC genotypes were similar between the two groups, and so was it with the C allele. The two SNPs had been in complete linkage disequilibrium (D'=1.0, r2=1.0).

CONCLUSIONThe rs416905 and rs402007 polymorphisms of the ADAMTS-1 gene may be associated with ischemic stroke caused by LAA. The C allele of the rs402007 locus may be a susceptibility factor for this subtype of stroke.

ADAM Proteins ; genetics ; ADAMTS1 Protein ; Aged ; Alleles ; Atherosclerosis ; complications ; Base Sequence ; Blood Glucose ; metabolism ; Brain Ischemia ; complications ; Fasting ; blood ; Female ; Gene Frequency ; Genetic Predisposition to Disease ; genetics ; Genotype ; Humans ; Logistic Models ; Male ; Middle Aged ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide ; Risk Factors ; Sequence Analysis, DNA ; Smoking ; Stroke ; blood ; etiology ; genetics